Spanish tax authorities are investigating 3,000 accounts at HSBC bank in Switzerland over possible unpaid taxes, the Spanish finance minister confirmed on Thursday.
Swiss authorities also confirmed they were investigating the information published on Wednesday by Spanish newspapers El País and Expansion about up to €6 billion (SFr8.16 billion) hidden in Swiss accounts.
Spanish Finance Minister Elena Salgado said the owners of the accounts had been notified and asked to clarify whether they had declared the money in the accounts.
"The account holders have been advised. They have to put the accounts in order with the Treasury and of course they will receive the corresponding sanctions and penalties," Salgado said in an interview with Spanish National Television on Thursday.
She declined to indicate the amount of money involved, but the business daily Expansion said the accounts could hold a total of around €6 billion.
The move comes as Spain's Socialist government is pushing ahead with tough austerity measures to slash its massive public deficit.
“They know that the fight against fraud is becoming more intense,” said Salgado.
Mario Tuor, head of communication for international financial matters at the Swiss finance ministry, told swissinfo.ch: “Switzerland is investigating the information published, but it cannot directly confirm or deny it.”
Since July 1, 2005, a savings tax agreement has been in force between Switzerland and the European Union, and a double-taxation agreement has existed between Spain and Switzerland for years, which was updated in 2009 to meet OECD standards.
According to the finance ministry, Switzerland collected SFr534.8 million in savings tax in 2009 on money earned in Swiss banks by EU citizens, which was then transferred to the respective European tax authorities. Some SFr26.3 million was transferred to Spain.
“But if this [bank] data was obtained illegally, Switzerland is not obliged to transfer the information,” a finance ministry spokesman told the Swiss News Agency.
El Pais said the accounts being probed are in the Swiss branch of the bank HSBC and that French authorities had tipped Spain off about them.
In January 2009, French officials, on a request from Swiss authorities, seized files stolen by an ex-employee of HSBC that included data on some 127,000 accounts held by people from 180 countries.
HSBC spokesman in Switzerland Pascal Dubey said the bank so far was in the dark about the Spanish investigation.
"The bank has Spanish clients. But we do not know if these were our stolen data that were given to Spain because we have not received any official confirmation from France or from Spain," he told Associated Press.
In a statement released on Friday, the Spanish tax office said “today" it could not conclude that tax fraud had been committed by the 3,000 accounts and for this reason the holders had been sent a note asking them to clarify their situation by June 30.
Spanish tax inspectors’ organisations IHE and GESTHA, denounced the "preferential treatment" given to the Spanish owners of the accounts in Switzerland.
But speaking on Spanish radio, the head of the Spanish tax office, Juan Manuel López Carbajo, rejected their accusations and said if taxpayers could not clarify their accounts, it would go “right to the end”.
López Carbajo said "there may be thousands of people affected" by the investigation and that not all of them were “in the same situation".
He told Onda Cero radio that Spain had started talks with Switzerland so that in the future this kind of bank information "would come directly and not through others".
He reiterated that the bank account information had come via the French authorities with whom Spain has information exchange agreements.
Work by international authorities to facilitate the exchange of information with so-called tax havens "is paying off", said the tax office chief.
"The barrier that existed, which has been so appealing for people wanting to hide their money, is crumbling," he concluded.
Simon Bradley, swissinfo.ch (With input from Andrea Ornelas)
Switzerland has been under continuous attack in the past 12 months for helping foreign tax evaders hide their assets. The global crusade coincided with the devastation of the financial crisis leaving large holes in the budgets of many countries.
The OECD placed Switzerland on a “grey list” of uncooperative tax havens in April last year. The Swiss were removed in September after renegotiating more than a dozen double taxation treaties, but they have refused to automatically transfer information to tax investigators without proof of crimes.
A former German finance minister referred last summer to the Swiss as Indians running away from the cavalry. His Italian counterpart said that he wanted to “bleed dry” the financial sector in the Italian-speaking part of Switzerland.
Several countries, including Italy, France, Britain and the US, launched tax amnesties last year in an effort to repatriate assets from tax cheats. These are forecast to damage the Swiss offshore banking industry.
Switzerland was particularly annoyed at the aggressive Italian amnesty that saw surveillance and tailing of cross border suspects going into Switzerland. The Swiss suspended talks on the new double taxation treaty in protest.
The most damaging tax evasion case involved the activities of UBS bank in the US. A year ago, UBS was fined $780 million after admitting helping US citizens to dodge taxes. It also handed over data of 285 account holders.
In September, the Swiss government agreed to transfer the details of 4,450 UBS clients to the US – in effect violating Swiss banking secrecy to prevent a ruinous court case for UBS.
Also last year a former employee of HSBC private bank in Geneva ran away with sensitive client data that he handed over to the French authorities.
In January an informant offered to sell the authorities in the German state of North Rhine-Westphalia the data of about 1,500 possible tax evaders with bank accounts in Switzerland.
In June the German government and the state of Lower Saxony said it had bought a CD said to contain the bank data of 20,000 alleged tax cheats with assets hidden in Switzerland.